Why would a model that ran successfully with the MLM estimator in version 2.0 NOT run successfully with either the MUML or MUMLM estimator in version 2.1. Using either the MUML or MUMLM estimators, one of the latent variables is undefined; that did not occur with MLM.

You would need to send the input or output and data to support@statmodel.com. The estimators were not changed. Only their names were changed. I would need to run your problem in both 2.0 and 2.1 to figure out what is happening.

I heard from your previous answer that the mplus version 3 (current version )is allowed for multi level SEM with non-recursive model. Now I already have mplus version 2, and want to run that model. Can I do that with version 2? Thank you very much